Smokeless powder.



ALLAN THOMAS COOKING, OF FOUR OAKS, NEAR BIRB'IINGHAM, ENGLAND.

sMonELEss POWDER.

Specification of Letters Patent.

Patented Nov. 17, 1908.

Application filed July 23, 1906. 7 Serial No. 327,367.

To all whom it may concern:

Be it known that I, ALLAN Tiroims Coon- ING, a subject of the King of Great Britain and Ireland, and residing at Carhampton House, Four Oaks, near Birmlngham, 1n the county of Warwick, England, have invented ,certain new and.useful Improvements in Smokeless Powders, oi which the following is a specification.

This invention relates to explosive compounds for use as propellents, and has for its object to produce an explosive which shall have such a regular and uniform rate of combustion as will give the bullet a high velocity with reasonable maximum pressure; which shall produce on combustion a solid residue adapted to act as a lubricant and neutralize acid products of combustion, thus preventing corrosion; and which shall have a moderate temperature of combustion, and so reduce erosion, without materially interfering with the smokeless quality of the powder, and i of alkali metals and alkaline earths is to pro have good chemical stability.

Further objects'of the invention are to reduce the volume and luminous character of the flame produced by combustion, to make the explosive compound suficiently plastic to enable it to be cut when dry without splintering, and to minimize the efiects of temperature on the ballistics oi' the explosive.

The invention consists in the addition to propellent explosives of a salt of the alkali metals, together with a salt of the alkaline earths, whereby after combustion a solid residue preferably in the form of a carbonate is produced. I

The invention further consists in the combination in an. explosive for propellent purposes of a carbonate forming salt of an alkali metal and a carbonate forming salt of an alkaline earth together with olive oil or like fixed oil. y

The invention further consists in an explosive containing the following ingredients in approximately the proportions given Nitro-glyccrin 30 to e0 parts.

bricating together Witha neutral carbonate formin salt of an alkali metal and a neutral carbonate forming salt of an alkaline earth, the proportions of these salts being preferably such as are-equivalent to about 0.55 parts of the carbonate of the alkali metal and 2.8- parts of the carbonate of the alkaline earth.

By a carbonateforming salt is meant a salt which when heated to a high temperature decomposes and leaves a residue of carbonate. I The invention further consists in the improvements in the manufacture of explosives hereinafter described.

In carrying the invention into effect, for--.

instance, where a potassium salt and a barium salt are used, a mixture consisting of barium tartrate 4; per cent. and potassium tartrate 0.9 per cent. is used. This mixture on combustion in the powder produces 2.8

'per cent. of barium carbonate and 0.55 per cent. of potassium carbonate. 7

The purpose oi the addition of the salts duce a solid residue preferably in the form of an alkaline carbonate which will lubricate the gun barrel, and also to neutralize any acid products of combustion which would otherwise cause corrosion, while at the same time producing an explosive which is substantially as smokeless as an explosive in wvhich barium tartrate without potassium tartrate is used and has substantially the lu- 7 properties of an explosive in which potassium tartrate without barium tartrate is used. For this purpose other carbonate forming salts of the alkali metals and alkaline earths than the tartrates above described may be used, and would produce the same final results or the carbonates themselves may be used in the first instance. It is preferred therefore to use salts such as the tartrates above mentioned which as is well known lower the temperature of the products of combustion. The acetates, citrates', oxalates or bicarbonates may be used for the same purpose it is especially desirable to use a salt which lowers the combustion temperature as a large proportion ,of nitroglyceringives a high temperature, and for small arm ammunition the amount of nitroglycerin should not be less than per cent. to

The salts of alkali metals and alkaline earths for-use as above described are preferably prepared by precipitating them in the form of an impalpable powder from a concentrated aqueous solutionby the addition of acetone, alcohol or other liquid which is miscible with Water and which is not a sol vent for the salt used.

In order to moderate the speed of combustion of the explosive if desired a small proportion of olive oil or other fixed oil f soluble in acetone, alcohol or other solvent used in the incorporation may be used in comblnat-ion with the salts above mentioned and Vaseline may also be used if desired as' described in the example hereinafter set out.

As an example of an explosive in accordance with this invention the following composition may be given Nitroglycerin 30 to 4:0 parts. Nitrocellulose GO to 50 parts. Vaseline 2.5 parts. Olive oil 2. 5 parts. Potassium tartrate 0. 9 part. Barium tartrate 4.0 parts.

The proportions of nitroglycerin and nitrocellulose may be varied Within the above limits, but for an explosive of moderate power the preferred proportion is 35 parts nitroglycerin and parts nitrocellulose.

The various constituents of the explosive are incorporated in any usual manner, for example, the nitrocellulose is first incorporated with the nitroglycerin; then the vaseline is incorporated with the olive oil and the mixed tartrates an'ialgamated therewith. This latter mixture is then thoroughly incorporated with the first or nitroglycerin nitrocellulose mixture until ahomogeneous plastic mass is obtained. To obtain the best results it is preferred to give the'explosive compound the shape of strips or flakes of ribbon section with longitudinal ribs. The purpose of the addition of olive oil orlike lixed oil soluble in acetone, alcoholor other solvent used in the incorporation, is to reduce the temperature of combustion, while olive oil also. has the important property of giving greater chemical stability to the compound. By the use of olive oil in combination with sha e of a double headed rail, regular and uni orm combustion is obtained, and also high velocity with a reasonable maximum pressure.

The combination ofthe use of salts which lower the temperature of combustion and the use of olive oil has also the advantage of minimizing the liability of explosives to give higher ballistic eflects when subjected to a higher temperature before or at the time of combustion. This result may be further eiiected by removing the small amount of solvent say 0.5 per cent. which remains in the explosive after it has been driedin the usual drying stove. This may be effected by treating the compound with steam or hot water and thus taking advantage of the affinity of the solvent for Water.

It is impossible to limit the application to tartrates or any one particular salt, of an alkalimetal and.an alkaline earth and at the same time adequately cover the invention as there are quite a number of these substances which are useful and the only characteristic which is common to all these salts is that they are formed with acids of high molecular weight and great heat of forma tion. Similar remarks also apply to the case of the oil as it is not thought necessary to limit this to olive oil or any particular oil and thus exclude other oils which are useful the only characteristic of the various useful oils common gto all being that they are oils of high molecular Weight and great heat. of :lormation.

Having now particularly described my in- \ention, I declare that what I claim is z-- 1. A propellent explosive consisting of a homogeneous plastic mixture containing nitrocellulose, nitroglycerin, a tartrate of alkali metal and a tartrate of an alkaline earth, as set forth;

2. A propellent explosive consisting oi a homogeneous plastic ,inixture containing nitrocellulose, nitroglycerin, potassium tartrate and barium tartrate, as set forth.

3. A propellent explosive consisting of a homogeneous plastic mixture containing nitrocellulose, nitroglycerin, potassium tartrate, barium tartrate and olive oil, as set forth.

4t. A propellent OXPlOSlVO consisting of a homogeneous plastic mixture of the following ingredients in approximately the pro- I I homogeneous plastic mixture of the followportion given.

mg ingredients in approximately the pro- N itroglycerin 30 to 40 parts; portlon glven' E Nitrocellulose 60 to 50 parts. Nitroglycerin 30 to 40 parts. 20 5 Vaseline 2. 5 Nitrocellulose 60 to 50 parts. Olive oil 2. 5 parts. Vaseline 2. parts. A carbonate forming neutral salt Olive oil 2.5 parts. of an alkali metal equivalentto, Potassium tartrate- 0. 9 part. 10 r 0.55 parts of the carbonate of the Barium tartrate 4;. O

parts. 25 In testimony whereof, I aflix my signature in presence of two witnesses.

ALLAN THOMAS COOKING. I Witnesses JOHN MORGAN, HARRY DAVIS.

alkali metal, and A carbonate forming neutral salt of an alkaline earth equivalent to 2.8 parts of the carbonate of the alkaline earth.

parts. I

5. A pro iellent explosive consisting of a 1 

